Scale dependence of the Young modulus measured by nanoindentation in columnar YSZ EB-PVD thermal barriers coatings
Résumé
Electron beam physical vapour deposited yttria stabilised zirconia (YSZ) thermal barrier coatings have been investigated by nanoindentation. It is shown that the mechanical properties, and particularly the Young modulus, of these coatings are closely related to their columnar microstructure. The transition from intra-columnar to inter-columnar deformation is characterised by a difference between the mechanical properties of the bulk YSZ and the ones of the coatings. The use of different indenter shape showed that the contact area was the parameter characteristic of this scale dependence. The deformation mechanisms studied by AFM have shown a good correlation with the evolution of the mechanical properties during the deformation.
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